Radar Direction Estimation Using Precomputed Elevation Vectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radar devices installed at a high height face challenges in accurately estimating the incoming direction of targets while minimizing computational complexity, especially when dealing with multiple targets and varying elevation angles.
Innovation Solution
A radar device with a transmission antenna inclined to extend along a line connecting the installation height and the ground, utilizing a plural antenna system processor configuration that includes a correlation matrix generator, distance estimator, and incoming direction estimator to calculate signal incoming directions using direction vectors with varying azimuth and elevation components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional direction estimation methods are used with radar installed at high height, then the system can detect targets, but the accuracy of signal incoming direction estimation deteriorates due to elevation angle variations
Solution Approach 1:
The patent pre-calculates and stores direction vectors corresponding to various elevation angles in a lookup table before actual signal processing. When a target is detected, the system simply retrieves the appropriate direction vector from the pre-computed table based on the estimated elevation angle, avoiding complex real-time calculations and significantly reducing computational complexity while maintaining high estimation accuracy.
Solution Approach 2:
The patent introduces elevation angle as an additional parameter in the direction estimation process. By incorporating elevation angle information into the direction vector calculations and using it to select appropriate vectors from the lookup table, the system adapts to the high-installation-height scenario where elevation variations significantly affect direction estimation accuracy.
2Speed
If mechanical antenna scanning is used to transmit and receive radio waves, then the system can detect targets, but the detection speed deteriorates due to long scanning time
Solution Approach 1:
The patent replaces mechanical antenna scanning with electronic beam forming using multiple antennas. The system simultaneously transmits and receives signals through multiple antenna elements, using electronic signal processing to achieve spatial filtering and target detection. This eliminates the need for slow mechanical movement while maintaining the ability to detect and track targets.
3Measurement precision
If pulse-modulated waves are transmitted with low range sidelobe characteristics, then the accuracy of distant target detection improves, but the reception dynamic range requirements increase to handle varying signal levels
Solution Approach 1:
The patent divides the reception processing into multiple channels, each handling specific signal level ranges. By segmenting the dynamic range handling across multiple processing paths with appropriate gain control, the system can effectively process both strong signals from nearby targets and weak signals from distant targets without requiring a single receiver to handle the entire dynamic range, thus reducing individual channel complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the accuracy of signal incoming direction estimation while reducing the computational load, allowing for precise target detection even at varying distances and angles.
Implementation Method 1
Radar devices radiate a radio-frequency radar transmission signal to the space from a measuring site
Implementation Method 2
receive a reflection wave signal reflected from a target
Data Source
AI summary
Each antenna system processor performs coherent integration on a prescribed number of correlation values between a reception signal and a transmission code. A correlation matrix generator generates a correlation matrix on the basis of coherent integration values. A distance estimator estimates a distance to a target. A direction vector storage is stored with direction vectors each of which includes an azimuth component with respect to a target and an elevation angle component of a line connecting a transmission antenna and the target in which a prescribed direction is used as a reference. An incoming direction estimator estimates a signal incoming direction from the target using the correlation matrix and the direction vectors in which the elevation angle component range is restricted on the basis of the distance to the target.